1. Field of the Invention
The present invention relates to a flat-type fluorescent lamp and a liquid crystal display (LCD) device having the flat-type fluorescent lamp. More particularly, the present invention relates to a flat-type fluorescent lamp capable of providing uniform luminance and an LCD device including the flat-type fluorescent lamp.
2. Description of the Related Art
An LCD device displays an image using a liquid crystal layer having optical characteristics such as anisotropy of refractivity and electrical characteristics such as anisotropy of dielectric constant. LCD devices can provide various desirable characteristics over cathode ray tube (CRT) or plasma display panel (PDP) devices, such as a thin profile, lower driving voltage, and lower power consumption.
An LCD panel is non-emissive type display device which requires a light source to supply the LCD panel of the LCD device with light for producing visible images.
The typical LCD device includes a cold cathode fluorescent lamp CCFL having a thin cylindrical shape that is extended in a predetermined direction. An LCD device having a large viewing area typically includes a plurality of CCFLs. As the number of CCFLs in the LCD device is increased, the manufacturing cost of the LCD device also increases, and optical characteristics such as luminance uniformity may be adversely affected.
Accordingly, a flat-type fluorescent lamp has been developed. The flat-type fluorescent lamp includes a lamp body having a plurality of discharge spaces and an external electrode through which a discharge voltage is applied to the lamp body. An inverter applies the discharge voltage to the external electrode to form a plasma discharge in the discharge spaces. An ultraviolet light generated in the discharge spaces is converted into a visible light by a fluorescent layer formed on an inner surface of the lamp body.
During operation of the flat-type fluorescent lamp, the luminance of the outer discharge spaces is lower than that of the central discharge spaces. The luminance difference is created by a parasitic capacitance between the flat-type fluorescent lamp and a metal receiving container. In addition the plasma discharge is not generated in the outer discharge spaces at low temperatures. As a result, the luminance uniformity and image display quality may be adversely affected.